[clang] Propagate lifetimebound from formal parameters to those in the canonical declaration and use that for analysis (PR #107627)

[Ilya Biryukov via cfe-commits]

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@@ -3227,6 +3227,41 @@ void Sema::mergeDeclAttributes(NamedDecl *New, Decl *Old,
   if (!foundAny) New->dropAttrs();
 }
 
+template <class T>
+static unsigned propagateAttribute(ParmVarDecl *toDecl,
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ilya-biryukov wrote:

NIT: maybe document that it returns a number of added attributes?

https://github.com/llvm/llvm-project/pull/107627